80 foot-pounds of work is needed to move the sofa in Tyler's apartment. Which of the following statements is true?

a.) If Tyler moves the sofa himself, he will do more work than if he gets a friend to help.

b.) If Tyler and his roommate move the sofa together, they will do half the amount of work.

c.) If the sofa does not move, no work is done.

d.)All of the above.